XF Custom Renderer for ImageCropper android library

public class ImagePickerService : IImagePickerService
    {
        public IImageSourceUtility ImageSourceUtility => new ImageSourceUtility();

        private void StartActivity()
        {
            var currentActivity = MainActivity.AppActivity;

            if (currentActivity != null)
            {
                var cropImageOptions = new CropImageOptions();
                cropImageOptions.MultiTouchEnabled = true;
                cropImageOptions.Guidelines = CropImageView.Guidelines.On;
                cropImageOptions.AspectRatioX = 1;
                cropImageOptions.AspectRatioY = 1;
                cropImageOptions.FixAspectRatio = true;
                cropImageOptions.Validate();
                var intent = new Intent();
                intent.SetClass(currentActivity, Class.FromType(typeof(ImagePickerOnResultActivity)));
                intent.PutExtra(CropImage.CropImageExtraSource, null as global::Android.Net.Uri); // Image Uri
                intent.PutExtra(CropImage.CropImageExtraOptions, cropImageOptions);
                currentActivity.StartActivity(intent);
            }
            else
            {
                throw new InvalidOperationException("Could not get current activity.");
            }
        }

        public Task<ImageSource> PickImageAsync()
        {
            StartActivity();

            return Task.Run(() =>
            {
                _waitHandle.WaitOne();
                var result = _pickAsyncResult;
                _pickAsyncResult = null;

                return result;
            });
        }

        private static ImageSource _pickAsyncResult;
        private static EventWaitHandle _waitHandle = new AutoResetEvent(false);

        // if crashes(in release mode after linking), see plugin desc for proguard config change required for this theme
        [Activity(Label = "CropImageActivity", Theme = "@style/Base.Theme.AppCompat")]
        //[Activity(Theme = "@style/Base.Theme.AppCompat")]
        public class ImagePickerOnResultActivity : Activity
        {
            protected override void OnCreate(Bundle savedInstanceState)
            {
                //base.OnCreate(savedInstanceState);

                // start activity
                var x = CropImage.Activity();
                    x.SetGuidelines(CropImageView.Guidelines.On)
                    .Start(this);
            }

            protected override void OnActivityResult(int requestCode, [GeneratedEnum] Result resultCode, Intent data)
            {
                if (requestCode == CropImage.CropImageActivityRequestCode)
                {
                    CropImage.ActivityResult result = CropImage.GetActivityResult(data);
                    if (resultCode == Result.Ok)
                    {
                        var croppedFileUri = new Uri(result.Uri.ToString());
                        _pickAsyncResult = ImageSource.FromFile(croppedFileUri.LocalPath);
                        _waitHandle.Set();
                    }
                    else if ((int)resultCode == CropImage.CropImageActivityResultErrorCode)
                    {
                        Java.Lang.Exception error = result.Error;
                    }
                }
            }
        }
    }